 /*******************************************************************************
  * Copyright (c) 2005 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.runtime.content;

 import java.io.*;
 import org.eclipse.core.runtime.QualifiedName;
 import org.eclipse.core.runtime.preferences.IScopeContext;

 /**
  * An object that performs content type matching queries.
  * <p>
  * This interface is not intended to be implemented by clients.
  * </p>
  *
  * @see IContentTypeManager#getMatcher(IContentTypeManager.ISelectionPolicy, IScopeContext)
  * @since 3.1
  */
 public interface IContentTypeMatcher {
     /**
      * Returns the preferred content type for the given contents and file name.
      * <p>
      * Returns <code>null</code> if no associated content types are
      * found.
      * </p>
      * <p>
      * If a file name is not provided, the entire content type registry will be
      * queried. For performance reasons, it is highly recommended
      * to provide a file name if available.
      * </p>
      * <p>
      * Any IOExceptions that may occur while reading the given input stream
      * will flow to the caller. The input stream will not be closed by this
      * operation.
      * </p>
      *
      * @param contents an input stream
      * @param fileName the file name associated to the contents, or <code>null</code>
      * @return the preferred content type associated to the given file name, or <code>null</code>
      * @throws IOException if an error occurs while reading the contents
      */
     public IContentType findContentTypeFor(InputStream contents, String fileName) throws IOException;

     /**
      * Returns the preferred content type for the given file name. If multiple content types
      * are associated with the given file name, the one considered the most appropriated will
      * be returned. If there are no content types associated, <code>null</code> is returned.
      *
      * @param fileName the name of the file
      * @return the preferred content type associated to the given file name, or <code>null</code>
      */
     public IContentType findContentTypeFor(String fileName);

     /**
      * Returns the content types associated to the given contents and file name.
      * <p>
      * Returns an empty array if no associated content types are found.
      * </p>
      * <p>
      * If a file name is not provided, the entire content type registry will be
      * queried. For performance reasons, it is highly recommended
      * to provide a file name if available.
      * </p>
      * <p>
      * Any IOExceptions that may occur while reading the given input stream
      * will flow to the caller. The input stream will not be closed by this
      * operation.
      * </p>
      *
      * @param contents an input stream
      * @param fileName the file name associated to the contents, or <code>null</code>
      * @return all content types associated to the given contents and file name
      * @throws IOException if an error occurs while reading the contents
      */
     public IContentType[] findContentTypesFor(InputStream contents, String fileName) throws IOException;

     /**
      * Returns all content types known by the platform that are associated to the given file name.
      * <p>
      * Returns an empty array if there are no content types associated.
      * </p>
      *
      * @param fileName the name of the file
      * @return all content types associated to the given file spec
      */
     public IContentType[] findContentTypesFor(String fileName);

     /**
      * Tries to obtain a description for the given contents and file name.
      * <p>
      * Any IOExceptions that may occur while reading the given input stream
      * will flow to the caller. The input stream will not be closed by this
      * operation.
      * </p>
      * <p>
      * If a file name is not provided, the entire content type registry will be
      * queried. For performance reasons, it is highly recommended
      * to provide a file name if available.
      * </p>
      *
      * @param contents the contents to be interpreted
      * @param fileName the file name associated to the contents, or <code>null</code>
      * @param options an array of keys for all properties that should be
      * described, or <code>IContentDescription.ALL</code>, for all of them
      * @return a content description if one could be obtained, or <code>null</code>
      * @throws IOException if an error occurs while reading the contents
      * @see IContentDescription
      */
     public IContentDescription getDescriptionFor(InputStream contents, String fileName, QualifiedName[] options) throws IOException;

     /**
      * Tries to obtain a description for the given contents and file name.
      * <p>
      * Any IOExceptions that may occur while reading the given input stream
      * will flow to the caller. The reader will not be closed by this
      * operation.
      * </p>
      * <p>
      * If a file name is not provided, the entire content type registry will be
      * queried. For performance reasons, it is highly recommended
      * to provide a file name if available.
      * </p>
      *
      * @param contents the contents to be interpreted
      * @param fileName the file name associated to the contents, or <code>null</code>
      * @param options an array of keys for all properties that should be
      * described, or <code>IContentDescription.ALL</code>, for all of them
      * @return a content description if one could be obtained, or <code>null</code>
      * @throws IOException if an error occurs while reading the contents
      * @see IContentDescription
      */
     public IContentDescription getDescriptionFor(Reader contents, String fileName, QualifiedName[] options) throws IOException;
 }
